[R] How to intepret a factor response model?
Maciej Bliziński
m.blizinski at wsisiz.edu.pl
Wed May 4 09:23:17 CEST 2005
Hello,
I'd like to create a model with a factor-type response variable. This is
an example:
> mydata <- data.frame(factor_var = as.factor(c(rep('one', 100), rep('two', 100), rep('three', 100))), real_var = c(rnorm(150), rnorm(150) + 5))
> summary(mydata)
factor_var real_var
one :100 Min. :-2.742877
three:100 1st Qu.:-0.009493
two :100 Median : 2.361669
Mean : 2.490411
3rd Qu.: 4.822394
Max. : 6.924588
> mymodel = glm(factor_var ~ real_var, family = 'binomial', data = mydata)
> summary(mymodel)
Call:
glm(formula = factor_var ~ real_var, family = "binomial", data = mydata)
Deviance Residuals:
Min 1Q Median 3Q Max
-1.7442 -0.6774 0.1849 0.3133 2.1187
Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) -0.6798 0.1882 -3.613 0.000303 ***
real_var 0.8971 0.1066 8.417 < 2e-16 ***
---
Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1
(Dispersion parameter for binomial family taken to be 1)
Null deviance: 381.91 on 299 degrees of freedom
Residual deviance: 213.31 on 298 degrees of freedom
AIC: 217.31
Number of Fisher Scoring iterations: 6
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For models with real-type response variable it's easy to figure out,
what's the equation for the response variable (in the model). But here
- how do I interpret the model?
--
God made the world in six days, and was arrested on the seventh.
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